Steinernema ichnusae sp. n. (Nematoda: Steinernematidae) a new entomopathogenic nematode from Sardinia Island (Italy)

A new Steinernema species was isolated from three different sandy soil samples along the Platamona Beach, in the north-west coast of Sardinia Island (Italy). This new species is characterized by the following morphological characters: infective third-stage juvenile with a body length of 866 ± 61 (767-969) μm, distance from head to excretory pore of 63 ± 2.7 (59-68) μm, tail length of 81 ± 3.2 (76-89) μm, ratio E (%) 77 ± 3.4 (68-83); male tail with a mucron only in the second generation, spicule length of 66 ± 1.4 (64-67) μm and gubernaculum length of 44 ± 1.4 (43-46) μm in the first generation male; female of first generation with a slight vulval protrusion and ratio D (%) of 53 ± 4.0 (47-63). The new species differs distinctly from the related species (S. feltiae, S. kraussei, S. litorale, S. oregonense and S. cholashanense) in some morphometric values such as percentage of hyaline portion, ratios of gubernaculum/spicule length, spicule head length/width. The DNA analyses of the internal transcribed spacers and D2D3 regions show that the studied nematode isolates are a new species. Cross hybridisation tests with S. feltiae, S. kraussei, S. litorale, S. weiseri and S. oregonense showed that these species were reproductively isolated.     

Susceptibility of the Colorado Potato Beetle and the Sugarbeet Wireworm to Steinernema feltiae and S. glaseri

In laboratory tests, larvae of the Colorado potato beetle (CPB), Leptinotarsa decemlineata (Say), and the sugarbeet wireworm (SBW), Limonius californicus (Mannerheim), were exposed to the nematodes Steinernema feltiae Filipjev (Mexican strain) (= Neoaplectana carpocapsae) and S. glaseri Steiner in soil. S. feltiae caused significantly higher mortality in SBW larvae than did S. glaseri, but both nematode species were equally effective against CPB larvae. The minimum concentration of S. feltiae for 100% mortality of CPB larvae after 13 days was 157 nematodes/cm² of soil, and the LC₅₀ based on 6-day mortality was 47.5 nematodes/cm²; in contrast, 100% mortality of SBW larvae was not achieved with even the highest concentration tested, 393 nematodes/cm². CPB adults emerging from nematode-contaminated soil were not infected. In field cage tests, S. feltiae applied to the soil surface at the rates of 155 and 310 nematodes/cm² soil caused 59% and 71% mortality, respectively, of late-fourth-instar spring-generation CPB, and 28% and 29% mortality, respectively, of SBW. No infection was obtained when larvae of summer generation CPB and SBW were placed in the same cages approximately 6 weeks after nematodes were applied to the soil. Inundative soil applications of S. feltiae, though cost prohibitive at present, were effective in reducing caged CPB and SBW field populations.     

Steinernema neocurtillis n. sp. (Rhabditida: Steinernematiclae) and a Key to Species of the Genus Steinernema

Steinernema neocurtillis n. sp. isolated from the mole cricket Neocurtilla hexadactyla Perty can be distinguished from other members of the genus by characteristics of the first-generation male and the third-stage infective juvenile (IJ). In the male, the distance from the anterior end to the excretory pore (DAE) is less than the body width at the excretory pore; D% (DAE divided by length of esophagus x 100) is low at 19. The gubernaculum legth is greater than three-fourths the spicule length. Range of the ratio gubernaculum length divided by spicule length is 0.82-0.93 in the first-generation male and 0.92-1.00 in the second-generation male. In the IJ, the distance from the anterior end to the excretory pore is extremely short (18 μm), causing the D% and E% (DAE divided by tail length x 100) to be low (D% = 23 and E% = 12). Average body length of the IJ is 885 μm.     

Characterization of Biocontrol Traits in Heterorhabditis floridensis: A Species with Broad Temperature Tolerance

Biological characteristics of two strains of the entomopathogenic nematode, Heterorhabditis floridensis (332 isolated in Florida and K22 isolated in Georgia) were described. The identity of the nematode’s symbiotic bacteria was elucidated and found to be Photorhabdus luminescens subsp. luminescens. Beneficial traits pertinent to biocontrol (environmental tolerance and virulence) were characterized. The range of temperature tolerance in the H. floridensis strains was broad and showed a high level of heat tolerance. The H. floridensis strains caused higher mortality or infection in G. mellonella at 30°C and 35°C compared with S. riobrave (355), a strain widely known to be heat tolerant, and the H. floridensis strains were also capable of infecting at 17°C whereas S. riobrave (355) was not. However, at higher temperatures (37°C and 39°C), though H. floridensis readily infected G. mellonella, S. riobrave strains caused higher levels of mortality. Desiccation tolerance in H. floridensis was similar to Heterorhabditis indica (Hom1) and S. riobrave (355) and superior to S. feltiae (SN). H. bacteriophora (Oswego) and S. carpocapsae (All) exhibited higher desiccation tolerance than the H. floridensis strains. The virulence of H. floridensis to four insect pests (Aethina tumida, Conotrachelus nenuphar, Diaprepes abbreviatus, and Tenebrio molitor) was determined relative to seven other nematodes: H. bacteriophora (Oswego), H. indica (Hom1), S. carpocapsae (All), S. feltiae (SN), S. glaseri (4-8 and Vs strains), and S. riobrave (355). Virulence to A. tumida was similar among the H. floridensis strains and other nematodes except S. glaseri (Vs), S. feltiae, and S. riobrave failed to cause higher mortality than the control. Only H. bacteriophora, H. indica, S. feltiae, S. riobrave, and S. glaseri (4-8) caused higher mortality than the control in C. nenuphar. All nematodes were pathogenic to D. abbreviatus though S. glaseri (4-8) and S. riobrave (355) were the most virulent. S. carpocapsae was the most virulent to T. molitor. In summary, the H. floridensis strains possess a wide niche breadth in temperature tolerance and have virulence and desiccation levels that are similar to a number of other entomopathogenic nematodes. The strains may be useful for biocontrol purposes in environments where temperature extremes occur within short durations.     

Aphelenchoides microstylus n. sp. and Seinura onondagensis n. sp. (Nemata: Aphelenchina) from New York

Aphelenchoides microstylus n. sp. and Seinura onondagensis n. sp., a nematode predator, are described from dead Scots pine (Pinus sylvestris L.) in Onondaga County, New York. Females of A. microstylus are 370 to 485 µm long. The body is slender and tapers posteriorly to an amucronate, pointed terminus. The head is continuous with the body, and lips bear a stylet guide. Diagnostic characters of females are three incisures in the lateral field, a short stylet (6-7.5 µm) with small basal knobs, a single row of oocytes, and a long postuterine sac (25-50 µm). Males are characterized by small spicules (10-11µm); two pairs of post-anal, subventral papillae; and a single row of spermatocytes. A bursa and gubernaculum are absent. Seinura onondagensis females are characterized by a body of moderate length (475-595 µm), finely annulated cuticle, and a slightly set-off head. Diagnostic characters are four incisures in the lateral field, long stylet without basal knobs (17-22 µm), single row of oocytes, and presence of a postuterine sac (14-38 µm). Males are unknown. The monospecific genus Indaphelenchus is proposed as a synonym of Seinura, and S. siddiqii n. comb. is proposed for the only species, I. siddiqii.     

Steinernema brazilense n. sp. (Rhabditida: Steinernematidae), a new entomopathogenic nematode from Mato Grosso, Brazil

A new entomopathogenic nematode, Steinernema brazilense n. sp., was isolated from a single soil sample collected from a natural forest in Mato Grosso do Sul state, Brazil. S. brazilense n. sp. is characterized morphologically by features of infective juveniles (IJ), males and females. For the IJ, body length averaging 1157 (1023-1284) μm, distance from anterior end to excretory pore 95 (87-102) μm, from anterior end to end of esophagus 148 (139-153) μm, tail length 85 (80-104) μm, D% and E% values 63 (58-70) and 106 (95-118.0), respectively. Lateral field pattern variable; the formula for the arrangement of ridges from head to tail is: 2, 4, 6, 8, 6, 2. For the male, the diagnostic characters include spicule averaging 83 (75-89) μm; D% about 65; the ratio SW% about 192. The length of spicule head is greater than width. Lateral field with one narrow ridge. First generation females are characterized by the presence of a ventral postanal swelling. S. brazilense n. sp. is morphologically close to Steinernema diaprepesi. It can be differentiated from S.diaprepesi by its longer IJ body length (1157 vs 1002 μm), longer distance from anterior end to excretory pore (110 vs 75 μm), a longer tail length (103 vs 83 μm); males of the new species with longer spicule (83 vs 79 μm). The new species can be distinguished further from other members of Steinernema glaseri group by characteristics of rDNA of ITS and D2D3 regions.     

Effectiveness of Steinernema spp. and Heterorhabditis bacteriophora against Popillia japonica in the Azores

Steinernema carpocapsae (Breton strain), S. glaseri, and Heterorhabditis bacteriophora were evaluated for their potential to control immature stages of the Japanese beetle, Popillia japonica, on Terceira Island (the Azores). In bioassays carried out at temperatures higher than 15 C, S. glaseri and H. bacteriophora caused 100% mortality of larvae, whereas S. carpocapsae caused 56% larval mortality. At temperatures slightly below 15 C, only S. glaseri remained effective. In field plots, in September, S. glaseri and S. carpocapsae reduced larval populations by 91% and 44%, respectively, when applied at the rate of 10⁶ nematodes/m². In April, S. glaseri caused 31% reduction in numbers of larvae, but S. carpocapsae was ineffective. In colder months (November-February) neither steinernematids nor H. bacteriophora reduced larval populations. Increasing the application rate from 10⁶ to 5 x 10⁶ infective stage S. glaseri per m² increased efficacy from 63% to 79% mortality.     

Soil Applications of Steinernematid and Heterorhabditid Nematodes for Control of Colorado Potato Beetles,Leptinotarsa decemlineata (Say)

Three strains of Steinernema feltiae Filipjev (All, Mexican, and Breton strains) and one of Heterorhabditis heliothidis (Khan, Brooks, and Hirschmann) were evaluated for their potential to control Colorado potato beetle (CPB), Leptinotarsa decemlineata (Say), larvae and pupae in the soil. In laboratory studies, H. heliothidis and S. feltiae (Mexican strain) produced the highest mortality (6 days posttreatment) of CPB when applied to the surface of a soil column containing mature CPB larvae 5 cm below. Mortality ranged from 80 to 90% at rates of 79-158 nematodes/cm². Similar results were seen in a field microplot study with all four nematodes; S. feltiae (Mexican strain) and H. heliothidis were most effective. Adult CPB emergence was reduced 86.5-100% after application of 31-93 H. heliothidis/cm² and 88.4-100% with 93-155 S. feltiae (Mexican strain)/cm². The All strain of S. feltiae was moderately effective (ca. 80% reduction at 93-155 nematodes/cm²), while the Breton strain was ineffective (< 40% reduction at 155 nematodes/cm²). In small plots of potatoes enclosed in field cages, application of H. heliothidis and S. feltiae (Mexican strain) at rates of 93-155 nematodes/cm² before larval CPB burial in the soil resulted in 66-77% reduction in adult CPB emergence. Soil applications of these nematodes show potential for biological control of CPB.     

Longidorus grandis n. sp. and L. paralongicaudatus n. sp. (Nematoda: Longidoridae), Two Parthenogenetic Species from Arkansas

Two new parthenogenetic species of Longidorus were found in Arkansas. Longidorus grandis n. sp. is characterized by its body (5.80-8.24 mm), slightly offset head, head width 20-27 µm, odontostyle 86-100 µm, guide ring 26-35 µm posterior to the anterior end, short conoid to mammiliform tail. Longidorus grandis n. sp. is similar to L. vineacola Sturhan &Weischer, 1964; L. lusitanicus Macara, 1985; L. edmundsi Hunt &Siddiqi, 1977; L. kuiperi Brinkman, Loof &Barbez, 1987; L. balticus Brzeski, Peneva &Brown, 2000; L. closelongatus Stoyanov, 1964; and L. seinhorsti Peneva, Loof &Brown, 1998. Longidorus paralongicaudatus n. sp. is characterized by its body length (2.60-5.00 µm), anteriorly flattened and offset head region 13-18 µm wide, odontostyle length 92-127 µm, guide ring 21-30 µm posterior to the anterior end, tail elongate-conical, and c'' = 1.2-2.6. Longidorus paralongicaudatus n. sp. most closely resembles L. longicaudatus Siddiqi, 1962; L. socialis Singh &Khan, 1996; L. juvenilis Dalmasso, 1969; and L. curvatus Khan, 1986.     

Morphologic and Genetic Evidence for Mixed Infection with Two Myxobolus Species (Myxozoa: Myxobolidae) in Gray Mullets,Mugil cephalus,from Korean Waters

The present study was performed to trace the decisive evidence for mixed infection of 2 Myxobolus species, M. episquamalis and Myxobolus sp., in the gray mullet, Mugil cephalus, from Korean waters. Mullets with whitish cyst-like plasmodia on their scales were collected near a sewage plant in Yeosu, southern part of Korea, in 2009. The cysts were mainly located on scales and also found in the intestine. The spores from scales were oval in a frontal view, tapering anteriorly to a blunt apex, and measured 7.2 µm (5.8-8.0) in length and 5.3 µm (4.7-6.1) in width. Two polar capsules were pyriform and extended over the anterior half of the spore, measuring 3.5 µm (2.3-4.8) in length and 2.0 µm (1.5-2.2) in width. In contrast, the spores from the intestine were ellipsoidal, 10.4 µm (9.0-11.9) in length and 8.4 µm (7.3-10.1) in width. The polar capsules were pyriform but did not extend over the anterior half of the spore, 3.7 µm (2.5-4.5) in length and 2.2 µm (1.8-2.9) in width. The nucleotide sequences of the 18S rDNA gene of the 2 myxosporean spores from scales and intestine showed 88.1% identity to each other and 100% identity with M. episquamalis and 94.5% identity with M. spinacurvatura from mullet, respectively. By the above findings, it is first confirmed that mullets from the Korean water are infected with 2 myxosporean species, M. episquamalis and Myxobolus sp.     

Freezing and Desiccation Tolerance in Entomopathogenic Nematodes: Diversity and Correlation of Traits

The ability of entomopathogenic nematodes to tolerate environmental stress such as desiccating or freezing conditions, can contribute significantly to biocontrol efficacy. Thus, in selecting which nematode to use in a particular biocontrol program, it is important to be able to predict which strain or species to use in target areas where environmental stress is expected. Our objectives were to (i) compare inter- and intraspecific variation in freeze and desiccation tolerance among a broad array of entomopathogenic nematodes, and (ii) determine if freeze and desiccation tolerance are correlated. In laboratory studies we compared nematodes at two levels of relative humidity (RH) (97% and 85%) and exposure periods (24 and 48 h), and nematodes were exposed to freezing temperatures (-2°C) for 6 or 24 h. To assess interspecific variation, we compared ten species including seven that are of current or recent commercial interest: Heterorhabditis bacteriophora (VS), H. floridensis, H. georgiana, (Kesha), H. indica (HOM1), H. megidis (UK211), Steinernema carpocapsae (All), S. feltiae (SN), S. glaseri (VS), S. rarum (17C&E), and S. riobrave (355). To assess intraspecific variation we compared five strains of H. bacteriophora (Baine, Fl1-1, Hb, Oswego, and VS) and four strains of S. carpocapsae (All, Cxrd, DD136, and Sal), and S. riobrave (355, 38b, 7-12, and TP). S. carpocapsae exhibited the highest level of desiccation tolerance among species followed by S. feltiae and S. rarum; the heterorhabditid species exhibited the least desiccation tolerance and S. riobrave and S. glaseri were intermediate. No intraspecific variation was observed in desiccation tolerance; S. carpocapsae strains showed higher tolerance than all H. bacteriophora or S. riobrave strains yet there was no difference detected within species. In interspecies comparisons, poor freeze tolerance was observed in H. indica, and S. glaseri, S. rarum, and S. riobrave whereas H. georgiana and S. feltiae exhibited the highest freeze tolerance, particularly in the 24-h exposure period. Unlike desiccation tolerance, substantial intraspecies variation in freeze tolerance was observed among H. bacteriophora and S. riobrave strains, yet within species variation was not detected among S. carpocapsae strains. Correlation analysis did not detect a relationship between freezing and desiccation tolerance.     

Longidorus paravineacola n. sp. (Nematoda: Longidoridae), a New Species from Arkansas

Longidorus paravineacola n. sp., described herein, was found in a survey of longidorids of Arkansas. It is a parthenogeneticspecies characterized by its long body (6.68-9.85 mm); slightly expanded and rounded head, head width 21-27 µm; odontostyle length 95-114 µm; guide ring 28-37 µm posterior to the head end; short rounded tail, and c'' = 0.6-1.0. Longidorus paravineacola n. sp. is similar to the amphimictic species L. vineacola Sturhan &Weischer, 1964; L. balticus Brzeski, Peneva &Brown, 2000; L. kuiperi Brinkman, Loof &Barbez, 1987; and parthenogenetic species L. crassus Thorne, 1974, which also occurred in the type locality.     

Myctolaimellus robiniae n. sp. (Diplogasterida: Cylindrocorporidae) from Larval Cavities of the Locust Borer,Megacyllene robiniae Forster

A new nematode species of the family Cylindrocorporidae and the genus Myctolaimellus from subcortical cavities made by the locust borer (Megacyllene robiniae Forster) in black locust (Robinia pseudoacacia L.) is described. Males of the new species have a length of 700 to 1,050 µm; a bursate tail, peloderan with nine pairs of rays; and knobbed, curved spicules with tips bending gently into a hook. The distinctive gubernaculum is half the length of the spicules, deeply grooved longitudinally along both its dorsal and ventral surfaces, and has a spoon-shaped end. Females have a length of 830 to 1,340 µm, an amphidelphic reproductive tract with long ovaries crossing each other to extend beyond the equatorial vulva, and a gradually tapering tail.     

Morphological and Molecular Characterization of Gracilacus wuae n. sp. (Nematoda: Criconematoidea) Associated with Cow Parsnip (Heracleum maximum) in Ontario,Canada

Gracilacus wuae n. sp. from soil associated with cow parsnip in Ontario, Canada is described and illustrated. Morphologically, females have a long stylet ranging from 80 to 93 µm long, the lip region not offset from the body contour, without lateral lips but with large and flat submedian lobes, the mouth opening slit-like elongated laterally and surrounded by lateral flaps, the excretory pore is anterior to the knobs of the stylet; males without stylet and the pharynx degenerated. The fourth-stage juveniles lack a stylet, the pharynx degenerated, and can be differentiated into preadult females and males based on the position of the genital primordia. The third-stage juveniles are similar to females but smaller. Phylogenetic studies using the rDNA small subunit 18S, large subunit 28S D2/D3, and internal transcribed spacer (ITS) sequences collectively provide evidence of a grouping with other Gracilacus and some species of Paratylenchus with stylet length of females longer than 41 µm deposited in GenBank.     

Description and SEM Observations of a New Species of Cyst Nematode Heterodera goldeni (Nematoda: Heteroderidae) Attacking Panicum coloratum in Egypt

A cyst nematode, Heterodera goldeni n. sp., is photographed and described from Qasabagrass roots (Panicum coloratum L.) in Alexandria, Egypt. It is characterized in having second-stage juveniles with body length of 546 µm (450-612), stylet length of 22.6 µm (22-23.5) with anchor-shaped knobs, lateral field with 3 lines, tail 60-75 µm, hyaline tail terminus 38.4 µm (33-43); cysts are lemon-shaped, dark to light brown with an extensive sub-crystalline layer covering the entire cyst, cuticular midbody pattern zig-zag, cysts ambifenestrate, well-developed underbridge with finger-like projections, bullae present, vulva slit measuring 44-48 µm long. Males are absent, and females have heavy punctations on the cuticle. Its relationship to H. graminophila described from Florida and Louisiana and H. leuceilyma described from Florida are discussed. The present known distribution is restricted to Alexandria, Egypt. Its economic importance in rangeland grasses and cultivated crops such as rice is not known.     

Descriptions of Deladenus albizicus n. sp. and D. processus n. sp. (Nematoda: Hexatylina) from Haryana,India

Two different nematodes were isolated from the bark of Albizia lebbeck trees; one from insect infested and another from noninfested, healthy tree. Based on the biological, morphological, and molecular evidences, the nematodes are described as Deladenus albizicus n. sp. and D. processus n. sp. (Nematoda: Hexatylina). Deladenus albizicus n. sp., isolated from insect-infested tree, multiplied on the fungus Nigrospora oryzae. Myceliophagous females of this nematode reproduced by parthenogenesis and spermathecae were indistinct. Infective females, readily produced in the cultures, are dorsally curved. Only one type of males containing small-sized sperms in their genital tracts were produced in the culture. Myceliophagous females: L = 0.75 to 1.71 mm, a = 32.3 to 50.8, b = 9.3 to 11.2, b’ = 5.2 to 7.3, c = 27.2 to 35.6, V = 91.0 to 93.3, c’ = 2.0 to 2.9, stylet = 11 to 12 µm, excretory pore in the region of median pharyngeal bulb, 43 to 47 µm anterior to hemizonid. Deladenus processus n. sp., isolated from bark of healthy A. lebbeck tree, was cultured on Alternaria alternata. Myceliophagous females reproduced by amphimixis and their spermathecae contained rounded sperms. Infective females were never produced, even in old cultures. Myceliophagous females: L = 0.76 to 0.99 mm, a = 34 to 49, b = 13.3 to 17.7, b’ = 3.8 to 5.8, c = 19.6 to 22.8, V = 92.2 to 93.5, c’ = 2.7 to 3.5, stylet = 6 to 7 µm, excretory pore in the proximity of hemizonid, tail conoid, tapering from both sides to a long pointed central process. It is proposed to classify Deladenus species in three groups: durus, siricidicola, and laricis groups based on female and spermatogonia dimorphism, mode of reproduction, and insect parasitism.     

Rhabditis (Oscheius) pheropsophi n. sp. (Rhabditida: Rhabditidae)

Rhabditis (Oscheius) pheropsophi n. sp., associated with cadavers of the bombardier beetle, Pheropsophus aequinoctialis, is described from material collected in Brazil. Mean body length of the female is 1,217 μm, of the male 872 μm, and of the dauer juvenile 568 μm. The female has six lips with one papilla on each lateral lip and two on each sublateral lip; stoma wall thickened dorsally, metarhabdions with warts, excretory pore near base of esophagus, tail long (c = 8), and phasmids prominent, protruding on scanning electron microscope preparations. The male has 10 pairs of bursal ribs, with the terminal pair considerably smaller than the others; spicules fused distally two-thirds of their length. The new species can be distinguished from other members of the Dolichura-group by its fused spicules.     

Pathogenicity of Two Species of Entomopathogenic Nematodes Against the Greenhouse Whitefly,Trialeurodes vaporariorum (Hemiptera: Aleyrodidae), in Laboratory and Greenhouse Experiments

The greenhouse whitefly Trialeurodes vaporariorum (Hemiptera: Aleyrodidae) is a polyphagous pest in greenhouse crops. The efficacy of two entomopathogenic nematodes (EPN), Steinernema feltiae and Heterorhabditis bacteriophora, as biological control agents against T. vaporariorum was evaluated using two model crops typical of vegetable greenhouse productions: cucumber and pepper. Laboratory tests evaluated adults and second nymphal instars for pest susceptibility to different EPN species at different concentrations of infective juveniles (IJ; 0, 25, 50, 100, 150, 200, and 250 IJ per cm²); subsequent greenhouse trials against second nymphal instars on cucumber and pepper plants evaluated more natural conditions. Concentrations were applied in combination with Triton X-100 (0.1% v/v), an adjuvant for increasing nematode activity. In laboratory studies, both life stages were susceptible to infection by the two nematode species, but S. feltiae recorded a lower LC₅₀ than H. bacteriophora for both insect stages. Similarly, in greenhouse experiments, S. feltiae required lower concentrations of IJ than H. bacteriophora to reach the same mortality in nymphs. In greenhouse trials, a significant difference was observed in the triple interaction among nematode species × concentration × plant. Furthermore, the highest mortality rate of the second nymphal instars of the T. vaporariorum was obtained from the application of S. feltiae concentrated to 250 IJ/cm² on cucumber (49 ± 1.23%). The general mortality caused by nematodes was significantly higher in cucumber than in pepper. These promising results support further investigation for the optimization of the best EPN species/concentration in combination with insecticides or adjuvants to reach a profitable control of this greenhouse pest.     

Description of Non-Type Seinura winchesi from Mushroom Compost (Nematoda: Seinuridae)

Non-type material identified as Seinura winchesi, and deposited in the collection of the Nematology Department, Rothamsted Experimental Station, England, is described. The material was collected from mushroom compost in Leeds, England, in 1957. Females of this population are characterized by a set-off head, knobless stylet (20-21 µm), two rows of oogonia-oocytes, and absence of a postuterine sac. The median bulb is oblong and, at times, is constricted in the middle. The body is 565 to 675 µm long and tapers posteriorly to a pointed terminus. The cuticle is finely annulated, and there are three incisures in the lateral field. The ovary is outstretched and overlaps the esophageal gland lobes. A spermatheca is present, and spermatozoa are visible. The vulva is posteriorly located (V = 77-80), and a flap is absent. Males are 550 to 680 µm long with a spicate tail that bears three pairs of subventral papillae. The spike is short (14-18 µm), about one-half the tail length. The testis is 360 to 412 µm long, not reflexed, and at times overlaps the esophageal gland lobes. Spermatogonia-spermatocytes are in two rows. Spicules are 14 to 15 µm long with a prominent apex, and small rostrum. A bursa and gubernaculum are absent.